[Mismatch repair gene mRNA expression in lung cancer tissues.]

To explore the expression of mismatch repair (MMR) gene mRNA in lung cancer and the relationship between mRNA expression and microsatellite alterations.

The mRNA expression of five MMR genes and six microsatellite markers were detected in 46 primary lung cancer tissues by RT-PCR and PCR-denature polyacrylamide gel electrophoresis-silver staining methods.

Reduced expression of five MMR gene mRNA was detected in 13. 0 %-32. 6 % of all 46 primary lung cancer tissues , and 58. 7 %(27/ 46) had one or more MMR gene mRNA expression reduced and 39. 1 %(18/ 46) had two or more MMR gene mRNA expression reduced. The reduced expression of MMR gene mRNA was more frequent in patients with lymph node metastasis (20/ 27 , 74. 1 %) than those without lymph node metastasis (7/ 19 ,36. 8 %) ( P < 0. 025) . Among microsatellite instability (MSI) and/ or loss of heterozygosity (LOH) (at 2 or more loci) positive samples , 95. 8 %(23/ 24) had decreased expression of MMR gene mRNA , but among MSI and/ or LOH negative samples , only 18. 2 %(4/ 22) had reduced expression of MMR gene mRNA , the difference was significant ( P < 0. 005) .

The function of MMR decreases in lung cancer tissue , and correlates with microsatellite alterations. MMR genes might play a role in carcinogenesis of lung cancer.